Integrated circuits (ICs) typically comprise numerous circuit components interconnected to perform the desired functions. Such circuit components include, for example, transistors such as field effect transistors (FETs). Interconnections are formed by forming contacts and conductive lines in a dielectric layer using, for example, damascene techniques. A damascene structure, for example, includes a via or contact hole in a lower portion and a trench which is generally wider than the contact hole in an upper portion. The via serves as a contact to a device while the trench contains the conductive line for connecting the device to, for example, other devices.
As critical dimensions (CD) continue to shrink, gaps between gates of transistors decreases. Various problems occur with decreasing gap sizes. For example, reliable gap fill can become a challenge as well as shorting between contacts.